I'd say that a lot of what this country is/has become is based on the beliefs and ideas of those old dudes that wrote the Declaration of Independence and the Constitution.
Take TJ for example....
"The rights of conscience we never submitted, we could not submit. We are answerable for them to our God. The legitimate powers of government extend to such acts as are injurious to others. But it does me no injury for my neighbour to say there are twenty gods, or no god. It neither picks my pocket nor breaks my leg . . . . Reason and free inquiry are the only effectual agents against error."
Jefferson's religious views became a major public issue during the bitter party conflict between Federalists and Republicans in the late 1790s when Jefferson was often accused of being an atheist.
Benjamin Franklin's religious beliefs? Six months before his death in 1790, Franklin summed up his religious creed in a letter to Ezra Stiles:
"I believe in one God, creator of the Universe. That he governs it in his providence. That he ought to be worshipped. That the most acceptable service we can render to Him is doing good to his other Children. That the soul of Man is immortal, and will be treated with Justice in another Life respecting its conduct in this. These I take to be the fundamental Principles of all sound Religion, and I regard them as you do in whatever Sect I meet with them.
As to Jesus of Nazareth, I think the System of Morals and his Religion, as he left them tous, the best the World ever saw or is likely to see; but I apprehend that it has received various corrupting changes, and I have, with most of the present Dissenters in England, some Doubts as to his Divinity; tho' it is a question I do not dogmatize upon, having never studied it, and think it needless to busy muself with it now, when expect soon an Opportunity of knowing the Truth with less Trouble.
I shall only add, respecting myself, that, having experienced the Goodness of that Being in conducting me prosperously thro' a long life, I have no doubt of its Continuance in the next, though without the smallest Conceit of meriting such Goodness."
John Adams?
"We should begin by setting conscience free. When all men of all religions ... shall enjoy equal liberty, property, and an equal chance for honors and power ... we may expect that improvements will be made in the human character and the state of society."
-- letter to Dr. Price, April 8, 1785, quoted from Albert Menendez and Edd Doerr, The Great Quotations on Religious Freedom (1991)
"As I understand the Christian religion, it was, and is, a revelation. But how has it happened that millions of fables, tales, legends, have been blended with both Jewish and Christian revelation that have made them the most bloody religion that ever existed?"
-- letter to F.A. Van der Kamp, December 27, 1816
So, to me... Religious Tolerance was a key ingredient. There's also clearly some warning or suspicion of what a lack of tolerance brings.
